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9 Things You Never Knew Could Be Measured

May 20th is World Measurement Day, a day to celebrate the weird and wacky world of measurement. The UK’s National Physical Laboratory (NPL) has been measuring things for 115 years. Here are some of the strangest.

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1. The world’s bluest sky

NPL / Via

NPL worked with Expedia to design the blue sky explorer, a portable spectrometer and camera rig which travelled the world to find the bluest sky on earth (although it only had a couple of days’ holiday in each location and was entirely at the mercy of the weather the whole time)

Rio de Janeiro came top, followed by Bay of Islands in New Zealand and Uluru in Australia.

And In the UK? Castell Dinas Bran in Wales came top, finishing ninth place overall.

2. Shininess of cats

Flickr: quinnanya

Yes, as strange as it may seem, NPL has measured the shininess of cats. Or, to be precise, the shininess of their fur. After all, you can't claim that your pet food makes cats shinier than any others' without backing it up with a machine to state the quantity. This requires an understanding of how humans perceive shininess and then the building of a machine that can 'see' it the way we do.

3. Fake Gucci dresses

Flickr: micosamardzija / Creative Commons

Counterfeit clothing and footwear costs designer brands and retailers around £3.5 billion each year. NPL fired electromagnetic waves at terahertz frequencies (between microwaves and infrared light) through different fabrics and found the waves scattered differently on different fabrics, producing characteristic 'signatures'. These could then be used to tell the difference between high and low quality fabrics, like plain wool and merino wool, for instance, or between natural and synthetic silks.

4. The exact width of lottery balls

Flickr: MickeyNP / Creative Commons / Via Flickr: 42442709@N00

Not everything in the National Lottery is down to luck - the numbered balls used in the selection process need to be manufactured in such a way they all have an equal chance of being chosen. To eliminate bias, balls used must all be the same size and mass.

NPL measured a pair of ‘GO' and 'NO GO' metal rings which varied by less than 0.001 of an inch in circumference. The balls were meticulously checked to ensure they all passed through the larger ring but were stopped by the smaller one.

5. Golf clubs to prevent cheating


Under the Rules of Golf, as governed by The R&A, golf equipment manufacturers cannot produce golf clubs that give players an unfair advantage.

The texture and form of the golf club surface that strikes the golf ball can have a great effect on the launch speed, spin and trajectory of the ball. NPL helped the R&A assess the surface texture of each new type of club and determine whether it conformed to the rules.

6. Robots that measure the ripeness of strawberries

Flickr: Fried Dough / Creative Commons / Via Flickr: 42787780@N04

NPL developed an imaging technology that can identify the ripeness of strawberries before they are picked. By passing microwave radiation through strawberries the water content (and therefore the ripeness) could be accurately determined. Adding this technology to fruit-picking robots could reduce food waste and improve productivity - not to mention help make the perfect glass of Pimms.

7. Cooling down the Commons


In the early 1920s NPL’s Engineering Department was asked to improve the ventilation in the debating chamber of the House of Commons. Experiments were carried out at NPL on a 1/8 scale model and improvements recommended. The direction of air flow in the model Chamber was demonstrated by observing smoke produced by a special firework - an excuse that didn't work for Guy Fawkes.

8. The perfect pants for combat

Edyta Pawlowska / Shutterstock

The MoD provides camouflage uniform for their troops to use in the day and night, down to regulation brown underwear. Tests undertaken by NPL on behalf of the uniform suppliers revealed that night vision systems, which use infra red, could detect certain types of underwear – giving away your location. This is an important discovery, as many troops prefer to wear their own pants rather than those issued to them!

9. The crunchiness of biscuits

Flickr: carowallis1 / Creative Commons

Stable Microsystems’ Acoustic Envelope Detector, measures the sounds from crunching and snapping foods. They tested biscuits in NPL’s anechoic chamber - where no sound can echo - to help food producers develop the perfect crunch. Why not have one now? Go on, you've earned it.